Certain benzotriazolylphenoxy tin compounds

ABSTRACT

COMPOUNDS OF THE FORMULA   RMSN(R&#39;&#39;Y-,2-(R&#39;&#39;X-,1-O(-)-BENZEN-2-YL)-2H-BENZOTRIAZOLE)RB   THEIR PREPARATION AND THEIR USE AS U.V. STABILIZERS FOR SYNTHETIC RESINS.

United States Patent 3,600,397 CERTAIN BENZOTRIAZOLYLPHENOXY TINCOMPOUNDS Toshio Seki, Osaka-shi, Kozaburo Suzuki, Kobe-shi, and TakashiMatsuzaki, Osaka-shi, Japan, assignors to Nitto Kasei Co., Ltd., Osaka,Japan N0 Drawing. Filed Aug. 25, 1966, Ser. No. 574,924 Claims priority,application Japan, Aug. 25, 1965, 40/ 51,406 Int. Cl. C07d 55/04 U.S.Cl. 260-299 22 Claims ABSTRACT OF THE DISCLOSURE Compounds of theformula their preparation and their use as U.V. stabilizers forsynthetic resins.

This invention relates to novel organotin compounds, to the preparationof such compounds, and to the use of these compounds as stabilizers forsynthetic resins.

It is known that certain organic compounds may be added to varioussynthetic resins to improve their resistance to deterioration inphysical properties on exposure to ultraviolet light. However, many ofthese compounds may be characterized as unsatisfactory because they aresubject to thermal decomposition, volatilization, or sublimation duringthe process of producing films, fibers, or other molded articles whichare heated. These compounds have a further defect because they actuallypromote the heatdeterioration of many synthetic resins, such aspolyvinyl chlorides. When the syntehtic resins are processed at atemperature above 200 C., these defects become even more pronounced. Inaddition, when these known stabilizers are added to fibers which are tobe washed or dry-cleaned, considerable discoloration due to the reactionof extremely small quantities of metal ion or cleaning material with thestabilizers may often be observed.

According to the present invention, these adverse effects may be reducedor eliminated by employing a new class of organotin compounds as lightstabilizers.

It is an object of this invention to provide novel organotin compounds.It is also an object of this invention to provide a method for preparingnovel organotin compounds. Still another object of this invention is toprovide stabilized synthetic resins containing novel organotin compoundsand methods of preparing such stabilized resins. Other objects will beapparent from the following description.

According to certain of its aspects, the method of improving lightfastness of synthetic resins of this invention comprises adding to thesynthetic resins one or more novel organotin compounds of the generalformula:

a wherein (a) each R is independently selected from the group consistingof an alkyl of 1-18 carbon atoms cycloalkyl, aryl, or benzyl, (b) each Ris independently selected from the group consisting of an alkyl of 1-12carbon atoms, alkoxy, hydrogen, and halogen, (c) each 3,600,397 PatentedAug. 17, 1971 ice R is bonded to a tin atom and is selected from thegroup consisting of the residue of a carboxylic acid of l-18 carbonatoms, mercaptan, mercapto acid ester, monoester maleate and a hydroxylgroup, (d) each of a and m is an integer 1-3, b is 0 or an integer 1-2,x and y are 0 or integers 1-3, and a+b+m=4. In all formulas,unsubstituted valences of the atoms are bonded to hydrogen atoms.

The organotin compounds having the aforesaid general formula may beprepared by heating a compound of the formula:

wherein R, x, and y have the same values as described for the foregoinggeneral Formula I, with a member selected from the group consisting of abis-triorganotin oxide, a triorganotin hydroxide, a diorganotin oxide,or mono-organotin oxide in an inert solvent medium such as benzene,toluene, etc. Instead of the organotin oxides, tri-, di-, ormono-organotin alkoxides may be employed in the reaction. Othercompounds within the general Formula I may be prepared by heating atriazole of Formula II with an organotin oxide, or a tri-, di-, ormono-organotin alkoxide in the presence of a mercaptan, mercapto acidester, carboxylic acid, or monoester maleate.

The novel organotin compounds formed by practice of this invention arecolorless to light yellow, crystalline or non-crystalline substances,depending upon the kind of R, R, and R" radicals, and the value of a, b,m, x, and y in the foregoing general Formula I. The compounds aresoluble in organic solvents having boiling points in the range of 40 C.to 300 C., e.g. aromatic hydrocarbon, alcohol, ether, ester, ketone,petroleum hydrocarbon, etc.

Examples of the organotin compounds which are within the scope of theinvention and which are suitable for use as light stabilizers includethe following:

( sH11)a 0 0 C.CH23

In the above examples, all unsatisfied valences are attached to hydrogenatoms.

These ultraviolet absorbers may be added to synthetic resins in severalways. For instance, the ultraviolet absorber may be added to thesynthetic resin reaction mixture before the preparation of the syntheticresin after which the admixture is polymerized and molded into films,fibers or other articles or it may be added to the synthetic resintogether with other additives such as a stabilizer, an anti-oxidant, acolorant, a mold lubricant, etc. by mixers, e.g. a ribbon blender, ahigh-speed mixer, a stirring mixer, etc. after which the mixture ismolded into films, fibers, or other articles. In addition, films,fibers, or other articles may be treated with solutions, suspensions oremulsions of the ultraviolet absorbers by immersing or spreading. It isalso possible to apply by adding the ultraviolet absorbers to solutions,suspensions, or emulsions of the synthetic resins.

The synthetic resin which may be stabilized by the method of thisinvention include ABS (acrylonitrilebutadiene-styrene) resins,cellulose, cellulose derivatives, acetal resins, fluoroplastics, acrylicresins, chlorinated polyethers, alkyd resins, amino resins, urethaneresins, epoxy resins, polyamide resins, phenoxy resins, furan resins,phenol resins, polyimides, polycarbonates, polyesters, polyethylenes,polypropylenes, polystyrenes, polyvinyl chlorides, synthetic rubbers,etc.

A preferred amount of the organotin compounds to be employed as theultraviolet absorber in the process of this invention is in the range of0.001 to 5% by weight based upon the weight of the synthetic resin,which will vary depending upon the kind of molded articles and themanner in which the organotin compounds are added.

The process of this invention is of great advantage to the production ofsynthetic resins when such resins are molded at a high temperature. Thisis a special commercial advantage, since conventional ultravioletabsorbers stimulate thermal decomposition, volatilization, etc. ofresins when treated at a temperature above C. When R" in Formula I isthe residue of mercaptan, mercapto acid ester, carboxylic acid ormonoester maleate in the foregoing general formula, the ultravioletabsorbers of the invention can also impart resistance to heat tosynthetic resins susceptible to the effects of thermal oxidation, e.g.ABS resins, chlorine-containing resins, polyolefins, etc.

In the following examples, there is provided a series of tests todemonstrate the effectiveness of the novel organotin compounds withregard to deteriorative effects of ultraviolet light on the syntheticresins stabilized in accordance with this invention, in comparison withthe eifects of various triazole compounds. Further comparisons are shownwithout any additives whatsoever. A black board which was set at anangle of 45 to the vertical and facing south was lined with testspecimens, and exposed outside. For each specimen, the followingproperties were observed: lowering of impact strength by Du Pont typeimpact machine, discoloration, and degree of cracking. In the examples,all parts are by weight unless otherwise indicated. All unsatisfiedvalences in the formulas of the examples are, unless otherwiseindicated, understood to be bonded to hydrogen atoms.

The following examples are submitted for the purpose of illustrationonly and are not to be construed as limiting the scope of the inventionin any way.

EXAMPLE 1 In order to provide a comparison as to the volatility by heatof the compounds (A) and (B), each compound was left in a Geer oven at180 C. for 0.5 hour and the weight losses were examined. Only 1.2% ofthe compound (B) disappeared compared with a 12% loss of the compound(A). The infra-red spectra of the compound (B) were almost the samebefore and after the last treatment.

0.5 gram of the compound (B) was added as an ultraviolet absorber to100' grams of styrene, the mixture was polymerized by heating at 100 C.for 2 days, and a sheet was made from the thus-obtained polymer. Theyellowing degree of the sheet was about 4 of that of the control sheetwhich was made by the same procedure as above but not containing theultraviolet absorber.

EXAMPLE 2 Two-tenths mole of 2-(2-hydroxy-5'-methyl phenyl)-benzotriazole (C) was reacted with mole of bis-(tributyltin)-oxide in200 cc. of benzene under reflux for 6 hours. The benzene was thendistilled otf under reduced pressure to give a compound (D) of theformula:

The compounds (C) and (D) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight-loss results:(C), 8.7%; (D), only 1.6%.

A film of polyethylene glycol terephthalate having a thickness of 0.05mm. was immersed in an acetone solution containing 2% by weight of thecompound (D) at 10 C. for 30 seconds, and was dried at 180 C. for 30seconds. The time at which the film obtained became fragile was morethan 3 times the time at which the untreated film did so when they wereexposed to ultraviolet light.

The toluene was then distilled off under reduced pressure to give acompound (F) of the formula:

The compounds (E) and (F) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight-losses: (E),4.2%; (F) only 0.9%.

milligrams of benzoyl peroxide and 0.5 gram of the compound (F) weremixed together in 400 cc. of methyl methacrylate and the solution waspolymerized and molded into hard plates of 2 mm. thickness. Denoted byimpact value, the brittleness on exposure to ultraviolet light of thethus obtained plate was /5 of that of a plate prepared by the sameprocedure as above but not containing the ultraviolet absorber.

EXAMPLE 4 Two-tenths mole of 2-(2-hydroxy-5-methyl phenyl)-benzotriazole (C) was reacted with mole of dibutyltin oxide in 200 cc.of benzene under reflux for 5 hours. The benzene was then distilled offunder reduced pressure to give a compound (H) of the formula:

The compounds (C) and (H) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight-losses: (C)8.7%, (H), only 1.7%.

0.2 part of the compound (H) was added to 2,000 parts of 5% polyvinylchloride solution in a-methylnaphthalene and the solution was spread outon a glass plate. The amethylnaphthalene was then stripped off from saidglass plate at C. for 10' minutes under reduced pressure to form acolorless, transparent thin cfilm of polyvinyl chloride. This film wasnot discolored by exposure to sunlight for 12 months.

For comparison, a film without the compound (H) and another film with0.2 part of the compound (C) were made by the. same procedure as above.The initial colors of the two films were yellow, and became brown afterexposure to the sunlight for 3 months in summer.

From these facts, it was concluded that the organotin compound (H) hadextremely low volatility and that it rendered the polyvinyl chloride(which otherwise deteriorated) stable not only to light, but also toheat.

EXAMPLE 5 One-tenth mole of 2-(2-hydroxy-3-methyl pheny1)- benzotriazole(I) was reacted with A mole of dibutyltin dimethoxide and mole ofmonobenzyl maleate in 200 cc. of toluene under reflux. The solvent wasthen distilled off under reduced pressure to give a compound (I) of theThe compounds (I) and (I) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight losses: (I),15%; (J), 2.0%.

3 parts of dibutyltin-bis-(benzyl maleate) as a stabilizer, 1 part ofdibutyltin dilaurate as a lubricant, 0.6 part of the compound (J), and0.4 part of the compound (H) used in Example 4 were mixed togetherthoroughly with 100 parts of vinyl chloride resin. The mixture wassheeted on a mixing mill heated at a surface temperature of 180 C. Thesheet obtained was colorless and transparent, and gave no colorationafter exposure to the sunlight over a long period of 32 consecutivemonths.

For comparison, a sheet not containing the compounds (J) and (H) wasprepared. Another sheet was prepared containing 1 part of the compound(I) instead of the compounds (J) and (H). The former was colorless andtransparent, and was not discolored after exposure to the sunlight for22 consecutive months, but the latter was light yellow in color, andturned brown after exposure to the sunlight for 12 months. From theseresults, it was found that the compound (I) might act no further as anultraviolet absorber since the compound (I) had accelerated the thermaldecomposition of the resins in the process of preparing the vinylchloride resins.

EXAMPLE 6 Two-tenths mole of 2-(2'-hydroxy phenyl)-benzotriazole (A) wasreacted with mole of monobutyltin oxide and mole of dodecyl mercaptan in200 cc. of toluene under reflux for 6 hours. The toluene was thendistilled off under reduced pressure to give a compound (K) of theformula:

The compounds (A) and (K) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight-losses: (A),12%; (K), only 1.6%.

Five-tenths percent of each of the compounds (A) and (K) was added toABS resins (acrylonitrile-butadienestyrene terpolymer) and each mixturewas injection molded into a flat plate. The plate containing thecompound (A) Was yellow in color but the plate containing the compound(K) was white in color, which shows that the compound (A) acceleratedthe thermal decomposition of the ABS resin. The time required to reducethe impact strength of the plate with the compound (K) to one-half bymeans of the irradiation of ultraviolet light was 9 to 11 times as longas that of the plate with the compound (A).

- EXAMPLE 7 Pwo-tenths mole of2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-4-chlorobenzotriazole (L) wasreacted with mole of tribenzyltin oxide in 200 cc. of heptane underreflux for 8 hours. The heptane was then distilled oif under reducedpressure to give a compound (M) of the formula:

The compounds (L) and (M) were tested for volatility by the sameprocedure as in Example 1 and gave the following weight-losses: (L),1.2%; (M), 0.4%.

Polypropylene containing 0.1% of 2,6-di-tertiary butyl- 4-methyl phenoland 0.2% of dilauryl thiodipropionate, and the mixture of saidpolypropylene with 0.3% of the compound (M) were melt extruded. Thefibers obtained were of pure white color in each case, whereas thefibers made from polypropylene with 0.3% of the compound (L) instead ofthe compound (M) waslight yellow in color. These fibers were washed withanion or non-ionic cleanser and dried in the sun repeatedly. Only thefibers with the compound (L) became yellow in color in several washingsand dryings. The time required for percentage maximum elongation of thefibers with the compound (M) to be reduced to half by the irradiation ofultraviolet light was 22 times as long as in the case of the fiberswithout any ultraviolet absorbers, and was 8 times as long as in thecase of the fibers with the compound (L).

EXAMPLE 8 Two-tenths mole of 2-(2-hydroxy diphenyl)-benzotriazole (A)was reacted with mole of dioctyltin oxide in 200 cc. of hexane underreflux for 4 hours. The hexane was then distilled off under reducedpressure to give a compound (N) of the formula:

The volatile losses of the compounds (A) and (N), tested by the sameprocedure as in Example 1, were 12% and 1.9% respectively.

1.5% of the compound (N) was added to polyethylene, and the mixture wasextruded into a film of 0.6 mm. thickness. For comparison, an additionalfilm was prepared from polyethylene without any additives by the sametechnique. Both of the films were colorless. These films were exposed toultraviolet light until their impact strength was reduced to one-half inorder to test them for resistance to ultraviolet light. As a result, thepolyethylene film containing the compound (N) had to be exposed 17 timesas long as one containing the compound (A).

Although this invention has been illustrated by reference to specificexamples, numerous changes and modifications thereof which clearly fallwithin the scope of the invention will be apparent to thoseskilled-in-the-art.

What is claimed is:

1. A compound of the formula:

)y 0: at

wherein:

(a) each R is independently selected from the group consisting of analkyl of 1-18 carbon atoms, cyclohexyl, phenyl, and benzyl,

(b) each R is independently selected from the group consisting of analkyl of 112 carbon atoms, methoxy, hydrogen, and halogen,

(0) each R" is bonded to the tin atom and is selected from the groupconsisting of alkanoyloxy of 1-18 carbon atoms, alkylthio of up to 12carbon atoms, a]kyloxycarbonylmethylthio wherein the alkyl is up to 8carbons, benzyl maleate, and hydroxyl groups,

(d) each of a and m is an integer 1-3, b is 0 or an integer l-2, x and yare 0 or integers 1-3, and a+b+m':4, and

(e) all unsubstituted valences of the atoms in Formula I are bonded tohydrogen atoms.

2. A compound according to claim 1 wherein b is 0, R is an alkyl groupof 1-18 carbon atoms and each R is independently an alkyl group of 1-12carbon atoms.

3. The compound:

9 4. The compound:

5. The compound:

N (CeHs 2)3 H; 6. The compound:

| 1 eHs)2 N\ 7. The compound:

r o N 8. The compound:

t-C4H N 4 02 C1 9. The compound:

SCH COOC HH al 02 g N 10. The compound:

GOG-0111123 (Ca 11)2 11. The compound:

(CAHQISK N 12. The compound:

13. The compound:

00 C-CH=CHC O O CHzCoHs (CAHMS I1 14. The compound:

15. The compound:

16. The compound:

19. The compound:

0 o 0011:0110 o o om 1 1 20. The compound:

SCuI-I C4I'I9SI1 N\ 21. The compound:

tC4H0- N oflfisonmsn s nh 22. The compound:

References Cited 15 ALEX MAZEL, Primary Examiner R. J. GALLAGHER,Assistant Examiner US. Cl. X.R.

